The present invention relates to a handle assembly, and particularly to an assembly having a one piece handle with an integrated appliance control switch and that is mounted to an extension tube containing electrical control wires for controlling a hand held, floor supported appliance, such as a vacuum cleaner.
A handle having a two piece clamshell construction for use with a vacuum cleaner is known. A handle having a clamshell construction facilitates the insertion of an appliance control switch into the handle and the mounting of the handle to an extension tube. However, such a two-piece handle is undesirable because one or more fasteners are usually required to hold the handle together, adding additional expense and manufacturing steps, and because fasteners may loosen during operation of the appliance.
A one piece handle is preferable to a two piece handle because a one piece handle does not require fasteners to hold it together. A simple one piece handle is an elastomeric handle that is fitted to the end of a tubular extension. Such a handle is often found on an inexpensive upright or stick type vacuum cleaner, and resembles those found on bicycle handle bars. The handle is usually mounted onto the tubular extensions by press fitting, heat shrinking, and/or with the use of adhesives. This simple handle, however, does not incorporate an electrical switch and provides a less than optimal ergonomic interface with an operator.
One piece handles with ergonomic features are known, but those handles do not provide integrated electrical switches and require fasteners for mounting the handles to their respective extension tubes. For example, the handle found on a vacuum cleaner sold under the trademark Combivac.TM. by Clarke.RTM., owned by McGraw-Edison Company, of Rolling Meadows, Ill., is a one piece molded handle manufactured using foam molding technology. The handle of the Combivac.TM. vacuum cleaner is attached to the tubular extension with a fastener and has an electrical switch located near the top of the vacuum cleaner body, not in the handle. A similar handle is shown in Wareham et al. U.S. Pat. No. 4,707,169 in which a handgrip is fixed to a handle by a fastener using a counter sunk bolt and nut.
It is undesirable to use fasteners to mount a handle to an extension tube for a variety of reasons. First, fasteners add expense to the fabrication of a handle because the fasteners themselves cost money and because additional labor is required for their assembly. Second, fasteners, such as set screws, normally make physical contact with the extension tube. Such contact may wear away or chip the paint or metal plating that protects the extension tube from oxidation. Third, fasteners may become loose over time, decreasing the dependability and strength of the handle. And fourth, fasteners that protrude inside an extension tube may cause an electrical hazard because the fasteners could damage the electrical wires inside the tube.
Even if a one piece molded handle having an integrated switch were known, that handle would be undesirable because that handle would likely be fabricated from a solid plastic form and require subsequent labor intensive methods. For example, a solid handle with a passage for receiving an extension tube and a port for mounting an integrated switch would be molded as a solid object and then bored to form the passage and switch port. The fabrication of a bored handle, however, would be expensive because the boring process would require substantial time and labor and would waste handle material. Moreover, if the handle is molded into the form of a loop, the loop itself would likely be solid, unnecessarily consuming additional plastic that adds undesirable weight to the handle.
The nitrogen gas-assist molding technique has been used to manufacture a handle that is lightweight, but has not been used to mold a handle that is mounted to an extension tube and that has an integrated switch for use with a floor supported appliance. Nitrogen gas assist molding techniques normally include the steps of (1) injecting a molten plastic into a cavity through a fluid injection port followed by the step of (2) injecting gas into the cavity to uniformly pack, or force, the molten resin against the cavity surface. This molding process provides high dimensional stability and superior strength, and reduces the weight of the product. Conventional nitrogen gas-assist molding techniques, however, do not describe a technique for making a handle assembly having a one piece molded handle that is mounted to an extension tube and that has an integrated switch for use with a floor-supported appliance.
It would therefore be desirable to provide a handle assembly having a lightweight one piece handle that has an integrated electrical control switch and that is mounted on an extension tube for use with floor supported appliances.
It would also be desirable to provide a handle that is mountable to an extension tube without fasteners.
It would further be desirable to provide such a handle that, when mounted to a plated extension tube, does not damage the plating.
It would even further be desirable to provide such a handle that has an ergonomic grip which is not constrained by wires, switches, or clamshell design and fasteners.
It would be even more desirable to provide such a handle that is durable, easy to assemble, and includes a minimum number of parts.
It is yet further desirable to provide methods for making such a handle and handle assembly.